<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>首页</title>
    <meta name="viewport" content="width=device-width,initial-scale=1">
    <link href="https://cdn.bootcss.com/twitter-bootstrap/3.4.1/css/bootstrap.min.css" rel="stylesheet">
    <script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.min.js"></script>
    <script src="https://cdn.bootcss.com/twitter-bootstrap/3.4.1/js/bootstrap.min.js"></script>
</head>
<body>
<input type="text" id="d1"> +
<input type="text" id="d2"> =
<input type="text" id="d3">
<p>
    <button id="btn">提交</button>
</p>
<script>
    //先绑定一个点击事件
    $('#btn').click(function (){
        $.ajax({

        })
    })
</script>


</body>
</html>